Probing the Orbital Energy of an Electron in an AtomJames L. BillsThis article answers an appeal for simple theoretical interpretations of atomic properties. A theoretical snapshot of an atom, showing the screened nuclear charge and the electron to be ionized at its radius of zero kinetic energy, enables anyone to approximate its ionization energy.Bills, James L. J. Chem. Educ.2006, 83, 473.

Atomic Properties / Structure |

Main-Group Elements |

Periodicity / Periodic Table |

Physical Properties |

Quantum Chemistry |

Theoretical Chemistry

The Meaning of d-Orbital LabelsGuy AshkenaziOrbital labels are the angular part of the wave function, expressed in Cartesian coordinates. The mathematical relation between the labels and the shapes of the orbitals is discussed. Ashkenazi, Guy. J. Chem. Educ.2005, 82, 323.

Response to Lowe's Potential-Energy-Only ModelsLowe, John P.Discussion of the suitability of a potential-only model for the successive ionization energies of sulfur for an introductory chemistry course.Lowe, John P. J. Chem. Educ.2002, 79, 430.

Ionization Energies, Parallel Spins, and the Stability of Half-Filled ShellsPeter CannThree methods for explaining the decrease in first ionization energies between group V and group VI elements are described and commented upon. The quantum mechanical origin of the unhelpful concept of half-shell stability is explained in terms of exchange energy, for which the alternative term parallel spin avoidance factor is suggested. It is recommended that for pre-university students the simplest explanation, in terms of Coulombic repulsion between two electrons occupying the same orbital, is adopted: it involves fewer difficult concepts than the other explanations and its predictions are no less accurate. Cann, Peter. J. Chem. Educ.2000, 77, 1056.

Atomic Properties / Structure |

Periodicity / Periodic Table |

Quantum Chemistry |

Theoretical Chemistry

The Genius of Slater's RulesJames L. ReedWith only a few modifications a procedure has been developed that yields the one-electron energies for atoms and ions with a level of detail very well suited for instruction in the structure and properties of atoms. It provides for the computation of very reasonable values for such properties as ionization energies, electron affinities, promotion energies, electronic transitions, and even XPS and ESCA spectra. Reed, James L. J. Chem. Educ.1999, 76, 802.

Atomic Properties / Structure |

Quantum Chemistry |

Theoretical Chemistry |

Spectroscopy

Deducing the Shell Model from Ionization Energies and the Use of Models in Introductory ChemistryRonald J. Gillespie, Richard S. Moog, and James N. SpencerA major objection of Rioux and DeKock is the statement in the authors' earlier paper that electron repulsion is responsible for the relative ionization energies of H and He. The commentators work clearly shows that a quantum mechanical treatment of this problem reveals that kinetic energy considerations play a crucial role in these values. However, although their criticism is appropriate in the context of this more sophisticated QM treatment, it does not in any way invalidate the authors original paper, the goal of which was to provide a model, namely the shell model, for the electronic structure of atoms that is consistent with experimental ionization energies.Gillespie, Ronald J.; Moog, Richard S.; Spencer, James N. J. Chem. Educ.1998, 75, 539.

Atomic Properties / Structure |

Quantum Chemistry |

Theoretical Chemistry

The Crucial Role of Kinetic Energy in Interpreting Ionization EnergiesFrank Rioux and Roger L. DeKockThe experimental ratio of the ionization energies of H and He is 1.81. The authors show that it is not correct to interpret this ratio using a classical Coulombic potential energy model. Rather a quantum mechanical model is required in which both kinetic and potential energy play a role. Rioux, Frank; DeKock, Roger L. J. Chem. Educ.1998, 75, 537.

Atomic Properties / Structure |

Quantum Chemistry |

Theoretical Chemistry

Teaching Chemistry with Electron Density ModelsGwendolyn P. Shusterman and Alan J. ShustermanThis article describes a powerful new method for teaching students about electronic structure and its relevance to chemical phenomena. This method, developed and used for several years in general chemistry and organic chemistry courses, relies on computer-generated three-dimensional models of electron density distributions.Shusterman, Gwendolyn P.; Shusterman, Alan J. J. Chem. Educ.1997, 74, 771.

Learning Theories |

Computational Chemistry |

Molecular Modeling |

Quantum Chemistry |

Atomic Properties / Structure |

Covalent Bonding |

Ionic Bonding |

Noncovalent Interactions

Electronic Configuration Pattern Found in Pascal's TriangleRobert L. DuncanA simple method for revealing the electronic configuration pattern within Pascal's Triangle is discussed. The origin of this unique pattern may be part of a combinatoric and is suggested a link may be made to quantum mechanics. Based on this triangular array an alternate representation of the Periodic Table is presented.Duncan, Robert L. J. Chem. Educ.1996, 73, 742.

Periodicity / Periodic Table |

Quantum Chemistry |

Atomic Properties / Structure

Moseley's Work on X-Rays and Atomic NumberC. W. HaighExplanation of the relationship between Moseley's work in determining atomic numbers, the spectrum of the hydrogen atom, the Bohr theory, and Slater's rules for screening constants.Haigh, C. W. J. Chem. Educ.1995, 72, 1012.

Pictorial analogies VII: Quantum numbers and orbitals Fortman, John J.Quantum number n is related to the size of a house, l is related to the shape of a house, and m is compared to the direction the house is facing. Pictures are included.Fortman, John J. J. Chem. Educ.1993, 70, 649.

Orbital plots of the hydrogen atomLiebl, Michael89. Bits and pieces, 36. The software described in this article enable a 48K Apple II with a single disk drive to plot the orbitals of the hydrogen atom in one, two, or three dimensions. This visualization of orbitals allows students to understand their importance in understanding chemistry.Liebl, Michael J. Chem. Educ.1988, 65, 23.

Why doesn't the electron fall into the nucleus?Mason, Franklin P.; Richardson, Robert W.This paper presents a simple, yet essentially correct model of the atom that can be used to answer the title question for even beginning students of chemistry.Mason, Franklin P.; Richardson, Robert W. J. Chem. Educ.1983, 60, 40.

Presenting the Bohr atomHaendler, Blanca L.A more significant consideration of the role of the Bohr theory in the development of quantum mechanics would have many benefits for introductory and advanced chemistry classes.Haendler, Blanca L. J. Chem. Educ.1982, 59, 372.

"The Dancing Wu Li Masters"Stapleton, George W.After reading "The Dancing Wu Li Masters", this author became convinced that the right person can explain the most difficult ideas in a clear, refreshing, and logical manner.Stapleton, George W. J. Chem. Educ.1981, 58, 574.

Using the Aufbau principle Whitmer, John C.This question is written with the belief that general chemistry students should not only attain an understanding of the Aufbau principle enabling them to write down electron configurations, they ought also recognize the correspondence between the quantum numbers and the structures of the periodic table.Whitmer, John C. J. Chem. Educ.1978, 55, 515.

Line spectrum demonstration for the large lecture hallDriscoll, Jerry A.The undergraduate's learning experience with quantum mechanics and Bohr's theory can be greatly enhanced by the presentation of a line spectrum demonstration, but these are often hard to see in large lecture halls. The authors present a physical arrangement of an apparatus that can be easily assembled to allow for easier student viewing in a lecture-hall situation.Driscoll, Jerry A. J. Chem. Educ.1974, 51, 97.

Atomic Properties / Structure |

Quantum Chemistry |

Spectroscopy

Forces and quantum field theoryBrescia, FrankThis article seeks to explain the nature of forces between nucleons in terms of the quantum field theory for the general reader using a simple analogy.Brescia, Frank J. Chem. Educ.1970, 47, 642.

Atomic orbitals: Limitations and variationsCohen, Irwin; Bustard, ThomasThe three most widely used methods of arriving at a set of atomic orbitals afford respective hydrogen-like orbitals, self-consistent field orbitals, and various analytical approximations such as the Slater or Morse orbitals, all of which may differ greatly in shape and size from each other.Cohen, Irwin; Bustard, Thomas J. Chem. Educ.1966, 43, 187.